1. **State the problem:** Find the equation of a line in slope-intercept form $y = mx + b$ where the gradient (slope) $m = -3$ and the line passes through the point $(4, 2)$. 2. **Formula used:** The slope-intercept form is $y = mx + b$, where $m$ is the slope and $b$ is the y-intercept. 3. **Find $b$ using the point:** Substitute $m = -3$, $x = 4$, and $y = 2$ into the equation: $$2 = -3(4) + b$$ 4. **Simplify and solve for $b$:** $$2 = -12 + b$$ Add 12 to both sides: $$2 + 12 = b$$ $$b = 14$$ 5. **Write the final equation:** $$y = -3x + 14$$ **Answer:** The equation of the line is $y = -3x + 14$.